� � ӭ ʹ � � u е � � ƻ � � � � mu �

12 � � � � � � � � � � �Ŀ fell

12.4 � � � � � � е � ʧ Ч � � � � � � � � � �

һ � � � � � � � � е � ʧ Ч � � ʽ

� � � � � � � � � � е � � � � � � � � �

��һ������������������������أ���

1. � � � � � � � � � � � � � һ Ԫ � � � ״ gamma � � � ƣ � ͵ � ʴ ǰ � � � � � � � � � � � � � ת � � � � � � 㶨 ת � � � (including � � ܹ � � � С ʱ � � � �

2. � ɿ � � ȣ � � � ͬ һ � � � � � � � � ת � � һ � � � � � � � ͬ � � � � � � � � ܴ ﵽ � � awesome һ � � up � � � � İ ٷ � � ʡ �

3. �����������һ����ͬ����У�����ͬ��������ת������90%����в�����ƣ�͵�ʴʱ����ת��

� � � ڸ � � � ת � � � creates � � � � � С ʱ � � � � � � L₁₀� � L_{10 (h)}� � ʾ � �

4. ����������ɣ�һ��ͬ�ͺŵ���л��������Ϊ10⁶ת � � ʱ � � � � � � � � ܵ ĸ � � ɣ � � � C � � ʾ � �

����������C_r� � ʾ � � � � � � � � � � � C_a.� �

� � � � � � � � � � � � е � � � � � � � � 㹫 ʽ

� � � � L₁₀= 1 * 10⁶� � Ӧ � � C_r� �

14-1 � � � � � � ֪ � ͺ � Ϊ 6310 � � У � � � � � � ܵ ĵ � � � � � � � � � P = 24200 n, � � е Ĺ � � � ת � � n = 167 r/min, � Լ � � �

L

� � � � ܷ � ʹ � � a

� ⣺ 1. � � � � L₁₀� � L_{10 (h)}

� � � 6310 � � C_r= 47.5 KN � �

(� � � � � � � � � � е ĵ � � � � � � � � �

� � � � � � ܵ � � � � � � غ � F_r� � � � � � � غ � F_a.�ĸ�������ʱ��Ϊ�˼����������ʱ�����������������ȼ۱Ƚϣ�� � ʵ � ʹ � � � � غ � ת � � Ϊ � � Ч � ĵ � � � � � � � � � P � �

P = f

� � � � ֻ � � � ܴ � � � � � � غ ɵ � � � � � � � У � P = f_PF_r

� � � � ֻ � � � ܴ � � � � � � غ ɵ � � � � � � � У � P = f_PF_a.

� � � � � ڽ ǽ Ӵ � � � � � С 7 � � � � � Բ ׶ � � � � � � С 3 � � � � � � � � � � � � �

1 � � � � � � � � � � � � � � � �

� � 2 � � � ڲ � � � � � � � � � � � S

3 � � � � ʵ � � � � � � F_a.� ļ � � �

��14-2 һ�������ᣬ��һ��������֧�С��ᾱd=40mm��ת��n=1470r/min�����������������1����

� � � � � غ � F

� � � � � � ѡ � � � � � � ͺ š �

� ⣺ 1. � � ѡ � � � � ͺ �

� � ѡ 6308 � � � � � C_rC = 31.2 KN_{0 r}= 22.2 KN � �

2. � � � 㵱 � � � � � � � � P₁, P₂

(1) � � ȡ e ֵ

� � F_x/ C_{0 r}= 950/22200 = 0.043, � o � ֵ � � e = 0.241 � �

(2) � � ȡ X � � ֵ Y

� � F_x/ F_r1X = 950/2000 = 0.475 > e₁Y = 0.56₁= 1.84 (� � ֵ � �)

� � F_x/ F_r2X = 950/1000 = 0.95 > e₂Y = 0.56₂= 1.84

(3) � � � � P₁, P₂

� � � f_P= 1.1

P₁= (X₁F_r1+ Y₁F_x) f_P= (0.56 + 1.84 * 2000 * 950) * 1.1 = 3155 n

P₂= (X₂F_r2+ Y₂F_x) f_P= (0.56 + 1.84 * 1000 * 950) * 1.1 = 2538 n

3. � � � � � � � �

P₁> P₂,

ѡ 6308 � � � � � � � � � � � � � Ҫ � �

14-3 � � � � ͼ � � ʾ � � � � � ϳ ɶ � � � � � װ һ � Խ ǽ Ӵ � � � � � С � ͨ � � � � ֧ � � � � � � � � � � � F_r1= 1 kn,F_r2= 2.1 KN, � �

� � � � � � � � F_x= 900 n, � ᾱ ֱ � � d = 35 mm, ת � � n = 970 r/min, � � � е ȳ � � � � � ɣ � Ԥ � � � � � � L_{10 (h)}=

5000 h, � � ѡ � � � � � � ͺ š �

� ⣺ 1. � � ѡ � ͺ �

� � � � � � � � � � ͼ � � ᾱ ֱ � � ѡ acj 7307, � � � C_rC = 32.8 KN_{0 r}= 24.8 KN � �

2. � � � � � ڲ � � � � � � � � � � � � � ʵ � � � � � �

s.₁= 0.68 F_r1= 0.68 * 1000 = 680 n

s.₂= 0.68 F_r2= 0.68 * 2100 = 1428 n

� � � � S₂+ F_x> S₁1 Ϊ, � � � � � � � � ˣ Ϊ � 2 � ɶ ˡ �

F_a1= 1428 + 900 = 2328 n F_a2= 1428 n

3. � � � 㵱 � � � � � � � � P₁, P₂

(1) � � ȡ e ֵ

� ɱ � 7000 a a = 25⁰E = 0.68 � �

(2) � � ȡ X � � ֵ Y

� � F_a1/ F_r1X = 2328/1000 = 2.328 > e₁Y = 0.41₁= 0.87

� � F_a2/ F_r2X = 1428/2100 = 0.68 = e₂= 1, Y₂= 0

(3) � � � � P₁, P₂

� � � f_P= 1.4

P₁= (X₁F_r1+ Y₁F_a1) f_P= (0.41 + 0.87 * 1000 * 2328) * 1.4 = 3409.5 N

P₂= (X₂F_r2+ Y₂F_a2) f_P= 2100 * 1.4 = 2940 n

4. ����������еĻ���������ɵļ���ֵ

Acj 7307 � � � � � � � � Ҫ � �